Methods and apparatus for adjusting blood circulation

Abstract

Embodiments of the invention include a method and a device for increasing blood flow and controlling the temperature of a mammal by applying a desired pressure to extremities of a mammal. The device generally includes a pliant body element that is adapted to receive a portion of an extremity of the mammal therein, and then apply a pressure to a portion of the extremity when a pressure is provided to a region in which the extremity is positioned within the pliant body element. By evacuating the region in which the extremity is enclosed, a contact surface area between the extremity of a mammal and the pliant body element is increased, due to the external atmospheric pressure acting on the pliant body element against the skin of the extremity of the mammal. The application of pressure assures that sufficient contact and thermal heat transfer (heating or cooling) is provided to the extremity of the mammal.

What is claimed is: 
     
       1. A method of preventing and/or reducing a risk of deep vein thrombosis (DVT) in an appendage of a mammal, comprising:
 cyclically varying pressure within an internal region of a flexible body of a device, wherein
 one or more first flexible walls of the flexible body at least partially enclose the internal region, and 
 the flexible body defines an outermost surface of a portion of the device, and the portion of the device is configured to be disposed over a portion of the appendage of the mammal when the portion of the appendage is disposed within the internal region through an opening that is formed within flexible body, and 
 
 wherein the method of cyclically varying pressure within the internal region comprises:
 (a) adjusting the pressure within the internal region to a first pressure level that is below atmospheric pressure, wherein the adjusted pressure causes the one or more first flexible walls to collapse against the portion of the appendage that is disposed within the internal region, and the flexible body is configured to substantially conform to the shape of the portion of the appendage when the first pressure level is achieved within the internal region; and 
 (b) adjusting the pressure within the internal region to a second pressure level; and 
 (c) repeating (a) and (b) at least one more time before removing the appendage from the internal region. 
 
 
     
     
       2. The method of  claim 1 , wherein the second pressure level is below atmospheric pressure. 
     
     
       3. The method of  claim 1 , wherein the second pressure level is above atmospheric pressure. 
     
     
       4. The method of  claim 1 , wherein the flexible body further comprises:
 one or more second flexible walls that are sealably coupled to at least a portion of the one or more first flexible walls to form a first enclosed fluid plenum region therebetween, and 
 the method further comprises flowing a thermal exchanging fluid at a first temperature through the first enclosed fluid plenum region. 
 
     
     
       5. The method of  claim 4 , wherein the first temperature is between about 30° C. and about 43° C. 
     
     
       6. The method of  claim 1 , wherein
 the adjusting the pressure within the internal region to the first pressure level further comprises adjusting the pressure to a level of about −20 mmHg and maintaining the first pressure level for a first period of time, and 
 then adjusting the pressure within the internal region to the second pressure level further comprises adjusting the pressure to a level between −3 mmHg and −20 mmHg and maintaining the second pressure level for a second period of time. 
 
     
     
       7. The method of  claim 6 , wherein the first temperature is between about 30° C. and about 43° C. 
     
     
       8. A method of preventing and/or reducing a risk of deep vein thrombosis (DVT) in an appendage of a mammal, comprising:
 cyclically varying pressure within an internal region of a flexible body of a device, wherein
 one or more first flexible walls of the flexible body at least partially enclose the internal region, 
 one or more second flexible walls are sealably coupled to at least a portion of the one or more first flexible walls to form a first enclosed fluid plenum region therebetween, 
 the flexible body defines an outermost surface of a portion of the device, and the portion of the device is configured to be disposed over a portion of the appendage of the mammal when the portion of the appendage is disposed within the internal region through an opening that is formed within flexible body, and 
 a flexible compression pad having an internal pocket region that is disposed over at least a portion of the appendage, and 
 
 wherein cyclically varying a pressure within the internal region comprises:
 (a) flowing a thermal exchanging fluid at a first temperature through the first enclosed fluid plenum region; 
 (b) adjusting the pressure within the internal region to a first pressure level that is below atmospheric pressure, wherein the adjusted pressure causes the one or more first flexible walls to collapse against the portion of the appendage that is disposed within the internal region, and the flexible body is configured to substantially conform to the shape of the portion of the appendage when the first pressure level is achieved within the internal region; and 
 (c) adjusting the pressure within the internal pocket region to a second pressure level; 
 (d) adjusting the pressure within the internal pocket region to a third pressure level; and 
 (e) repeating (c) and (d) at least one more time before removing the appendage from the internal region. 
 
 
     
     
       9. The method of  claim 8 , wherein the second pressure level is below atmospheric pressure. 
     
     
       10. The method of  claim 8 , wherein the second pressure level is above atmospheric pressure. 
     
     
       11. The method of  claim 8 , wherein the first temperature is between about 30° C. and about 43° C. 
     
     
       12. The method of  claim 8 , wherein
 the adjusting the pressure within the internal region to the first pressure level further comprises adjusting the pressure to a level of less than or equal to −20 mmHg and maintaining the first pressure level for a first period of time. 
 
     
     
       13. The method of  claim 12 , wherein the first temperature is between about 30° C. and about 43° C. 
     
     
       14. A method of preventing and/or reducing a risk of deep vein thrombosis (DVT) in a mammal using a device, comprising:
 positioning at least a portion of an extremity of a mammal in an internal region of a flexible body, wherein the flexible body comprises:
 one or more first flexible walls that enclose at least a portion of a first internal region, wherein at least a portion of the flexible body defines an outermost surface of a portion of the device; 
 an opening formed in the flexible body that is configured to receive the portion of the extremity and allow the portion of the extremity to be positioned within the first internal region; 
 one or more second flexible walls sealably coupled to at least a portion of the one or more first flexible walls to form a first enclosed fluid plenum region therebetween; and 
 
 varying the pressure within the first internal region between a first pressure level and a second pressure level using:
 a first pump fluidly coupled to the first internal region and that is configured to generate a pressure below atmospheric pressure within the first internal region to cause the one or more first flexible walls to collapse against the portion of the extremity disposed in the internal region, wherein the flexible body is configured to substantially conform to the shape of the portion of the extremity when the first pressure level is reached within the first internal region. 
 
 
     
     
       15. The method of  claim 14 , further comprising:
 positioning a first compression pad over at least a portion of the extremity, wherein the first compression pad comprises a third flexible wall that encloses at least a portion of a second internal region; and 
 controlling the pressure in the second enclosed plenum region using:
 a second pump fluidly coupled to the second enclosed plenum region and configured to create a pressure above atmospheric pressure within the second internal region to cause the third flexible wall to press against the at least a portion of the extremity. 
 
 
     
     
       16. The method of  claim 14 , wherein the second pressure level is below atmospheric pressure. 
     
     
       17. The method of  claim 14 , further comprising flowing a thermal exchanging fluid at a first temperature through the first enclosed fluid plenum region, wherein the first temperature is between about 30° C. and about 43° C. 
     
     
       18. The method of  claim 14 , wherein
 varying the pressure within the internal region to the first pressure level further comprises adjusting the pressure to a level of less than or equal to −20 mmHg and maintaining the first pressure level for a first period of time.